1. Field of the Invention
The present invention relates to a charge transfer analog comparator.
2. Description of the Prior Art
To the knowledge of the applicant, no such comparators exist at the present time.
However in some applications using charge transfer devices, it is sometimes necessary to compare two charge amounts with each other. This is in particular the case with charge transfer devices used as multilevel analog memories in which the information is stored in the form of calibrated charge packets which are periodically regenerated and reinjected. The calibration and recalibration operation during each reinjection is accomplished with N comparators which locate the position of the charge packet with respect to a reference signal corresponding to N reference charge packets. This operation is usually accomplished by converting the voltage charge packets and by using voltage comparators of a known type.
The purpose of the present invention is to overcome this disadvantage by providing a comparator which effects the comparison directly at the level of the charge packets and consequently avoids charge-voltage conversions.